Hub for releasably holding a reel



April 4, 1967 M. F. MERTENS 3,312,411

HUB FOR RELEASABLY HOLDING A REEL I Filed June 2. 1965 5 Sheets-Sheet 1 Attorney Inventor April 4, 1967 D. M. F. MERTENS 3,312,411

HUB FOR RELEASABLY HOLDING A REEL 3 Sheets-Sheet 2 Filed June 2, 1965 F/GS.

In venior I570 ORUS D. M 1 MEIQTEIVS April 4, 1967 l. D. M. F. MERTEYNS 3,3

HUB FOR RELEASABLY HOLDING A REEL Filed June 2, 1965 3 Sheets$heet 5 I lnvenlar lS/DORl/S 0. M. A MERTEIVS By M7 A Home y United States Patent Ofiice 3,312,411 Patented Apr. 4, 1967 3,312,411 HUB FOR RELEASAELY HOLDING A REEL Isidorus D. M. F. Mertens, Niel, Belgium, assignor to International Standard Electric Corporation, New York, N.Y., a corporation of Delaware Filed June 2, 1965, Ser. No. 460,643 Claims priority, application Netherlands, July 13, 1964, 6,407,957 10 Claims. (Cl. 242-683) This invention relates to a hub for releasably holding a reel, such as a magnetic tape reel, comprising a housing having an external supporting surface for said reel and being adapted to be secured to a rotatable shaft, a plurality of pawls carried by said housing and capable of being radially moved with respect to said housing, said pawls each having an outer surface of said reel, and displacement means including a rotatable knob and adapted to engage said pawls with said reel and to urge said pawls out of engagement from said reel.

Such a hub is already known from the U.S. Patent 2,983,460. Therein the rotatable knob is operatively associated with a spider coupled with the plurality of pawls in such a manner that by screwing or unscrewing the knob the spider is axially displaced and hereby radially moves these pawls into engagement with or out of engagement fro-m the reel. 1

It is therefore an object'of the present invention to provide an improved, simple and reliable hub of the type mentioned which may be brought quickly into its rest and operative positions.

Another object of the present invention is to provide a hub of the type mentioned which is brought into its rest and operative positions by snap-action.

The present hub is characterized in that said displacement means include at least one cam able to be pivoted by said knob about a pivot axle from a first stable position to a second stable position and mounted in said housing in such a manner that when said cam is pivoted into said second stable position it moves said pawls into engagement with said reel.

The above mentioned and other objects and features of the invention will become more apparent and the invention itself will be best understood by referring to the following description of an embodiment taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a front view of a hub according to the invention;

FIG. 2 shows a top view of this hub; 7

FIG. 3 represents a cross-section along the line III-III of FIG. 1;

FIG. 4 is a cross-sectional view along the line IVIV of FIG. 3; and

FIG. 5 shows a cross-section along the line VV of FIG. 3.

Referring to these figures, the hub shown comprises a housing, generally indicated by 1, having an external cylindrical supporting surface 2 to the front edge of which is welded a ring-shaped part 3, delimiting an opening 4, and which is integral with a radial flange 5. At its one side the radial flange 5 is integral with a cylindrical base part 6 which is concentric to the supporting surface 2 and the front face of which has a cylindrical cavity 7. A pin 8 is further welded on this front face. At its other side the radial flange 5 is integral with a cylindrical hub 9, this hub and the base part 6 being provided with a cylindrical opening 10 and a keyway 1:1. The housing 1 comprises the three pairs of side walls 12, 13, 14, and 16, 17 spaced 120 apart and extending in the direction of the base part 6. Each of these pairs of side walls delimits a respective channel 18, 19, 20 which extends at the one end in the ring-shaped part 3 and at the other end through the radial flange 5 (FIG. 2) where it is radially prolonged by the respective slots 21, 22, 23. Each of these channels 18, 19, 20 is widened over a portion of its length by axial cuts which communicate with a radial incision made through the housing 1 and the side walls delimiting the channel. For instance, as represented in FIG. 2, the channel 18 is widened over a part of its length by the axial cuts 24, 25 which communicate with the radial incision 26, 27 made through the housing 1 and through the side walls 12, 13 delimiting this channel 18.

In each of the channels 18, 19, 20 is mounted a respective pawl 28, 29, 30 each provided with a respective hook 31, 32, 33, these hooks defining a surface parallel to the radial flange 5. Each of these pawls has a wider portion adapted to be located in the wider portion of the channel. For instance, as represented in FIG. 2, the pawl 28 has a wider part located in the wider portion 24, 25 of the channel 18. In each of the pawls 28, 29, 30 is inserted a respective pin 34, 35, 36 and in a cavity of each of these pawls 2'8, 29, 30 is loosely mounted a respective ball 37, 38, 39 maintained in position by grease only. It should be noted that the radial incisions such as 26, 27 have been provided in order to be able to easily bring the pins, such as 34, of the pawls, such as 28, in their respective channel, such as 18. Three blade springs 40, 41, 42 are secured to the inner surface of the housing 1 by means of two screws and a small plate. For 'instance, as represented in FIG. 3, the blade spring 41 is secured by means of the screws 43, 44 and the small plate 45. The fixing screws of the blade springs 40, 42, are not visii'ble in the drawings but the respective small fixing plates areindicated by 46, 47. The blade springs 40, 41, 42 urged the balls 37, 38, 39 of the pawls 2 8, 29, 30 into contact with the cam 48 since they exert a pressure on the pins 34, 35, 36 inserted in these pawls.

The hub is fixed on the portion 49 of a shaft 50 by means of a key 51 engaged in the keyway 11. The shaft '50 further has a threaded portion 52 on which is slid a washer 53 and on which are screwed the nut 54 and the locking washer 55. The above cam 48 is loosely mounted on the portion 56 of the shaft 50 and between the shaft portions 57 and 52, a washer 58 being arranged between the shaft part 57 and the cam 48. This cam has an arcuate slot 59 which is concentric with the shaft part 56 and through which projects the pin 8. The peripheral surface of the cam 48 has three identical port-ions 60, 6'1, 62 the distance between the surface of each portion and the axis of the shaft part 56 gradually increasing from a minimum value to a maximum value.

An attachment pin 63 is fixed on the cam 48 and connected to the attachment hook 64 fixed on the housing 1, by means of the spring 65. The circular plate 66 is further fixed on the cam 48 by means of the screws 67, 68 this circular plate 66 having a diameter equal to that of the opening 4. A knob 69 is connected to the circular plate 66 by means of the pin 70.

The operation of the above described hub is as follows. In the rest position (not shown) of the hub the pin 8 is maintained in contact with the left hand e-nd (FIG. 4) of the arcuate slot 5 9 in the cam 48 by the spring 65 which tends to pivot the cam 48 in counterclockwise direction. Thus the cam 4-8 is in a first stable position. In this position the blade springs 40, 41, 42 urge the balls 37, 3'8, 39 of the respective pawls 28, 29, 30 into contact with the respective peripheral parts 60, 61, 62 at the place where the latter are located at their smallest distance from the shaft part 56. Hence the pawls 28, 29, 30 and their respective hooks 3 1, 3'2, 33 are retracted beyond the cylindrical external supporting surface 2 of the hub.

. then pivoted in clockwise direction till the right hand end of the arcuate slot 59 makes contact with the fixed pin 8. The cam 78 is maintained in this second stable condition by the spring 65 which now .tends to pivot the cam in clockwise direction. During the pivotal movement of the cam 4-8 from its first stable position towards its second stable position, the pawls 28, 2-9, 3ft are radially moved with respect to the housing due to the fact that the cam parts 60, 6 1, 62 exert a pressure on the balls 37, 38, 39 of the pawls 28, 29, 30 against the action of the blade springs 40, 411, 42. The outer surface of the pawls 28, 29, 39 are thus engaged in the respective grooves of the reel so that the latter is fixedly secured to the hub and that a relative radial displacement with respect to this hub is rendered impossible. An axial displacement of the reel with respect to the hub is also rendered impossible due to the presence of the hooks 31, 3Q, 33.

Instead of being provided with grooves the inner surface of the reel could also be flush with the external supporting surface 2 of the hub. Grooves are however preferred since in this case a positive reel drive is provided. It should be noted that the ball bearings 37, 38 3% have been used in order that the respective pawls Z8, 29, 30 should only make contact with the cam 48 along a very small friction surface. Thus one is sure that the forces exerted by the reel on the cam 48 will always be directed towards the axis of the pivot axle 55 of this cam, so that the latter cam 48 can never be angularly displaced under influence of such forces.

While the principles of the invention have been described in connection with specific apparatus, it is to be clearly understood that this description is made by way of example and not as a limitation on the scope of the invention.

I claim:

1. A hub for releasably holding a reel, such as a magnetic tape reel, comprising a housing having an external supporting surface for said reel and being adapted to be secured to a rotatable shaft, a plurality of pawls carried by said housing and capable of being moved in only a radial direction with respect to said housing, said pawls each having an outer surface for engaging a supporting surface of said reel, and resiliently-biased, snap-acting; displacement means including a rotatable knob and adapted to engage said pawls with said reel and to urge said pawls out of engagement with said reel, said resiliently-biased, snap-acting displacement means having a first stable position and a second stable position and including at least one cam able to be pivoted by said knob about a pivot axle from said first stable position to said second stable position and mounted in said housing in such a manner that when said cam is pivoted into second stable position it moves said pawls into engagement with said reels.

2. A hub as claimed in claim 1, wherein said resilientlybiased, snap-acting displacement means further include spring means mounted in said housing and adapted to urge said pawls out of engagement from said reel when said cam is in said first stable position and to maintain said pawls continuously into contact with said cam.

3. A hub as claimed in claim 2, wherein said spring means are constituted by blade springs each secured to the inner surface of said housing between each two adjacent pawls.

4. A hub as claimed in claim 1, wherein each said cam has an outer peripheral surface part located at a distance from said pivot axle which substantially gradually increases from the place where said outer peripheral surface part makes contact with said pawl when said cam is in said first stable position towards the place where said outer peripheral surface part makes contact with said pawl when said cam is in said second stable position.

5. A hub as claimed in claim 4, wherein said resilientlybiased, snap-acting displacement means include a single said cam having a plurality of said outer peripheral surface parts equal to said plurality of pawls.

6. A hub as claimed in claim 5, wherein said cam has an arouate slot which is concentric with said pivot axle, .a pin secured to said housing projects through said slot, and said cam is connected to said housing in such a manner that when said cam is in its said first and second stable positions a spring connected between said cam and said housing maintains said pin in contact with the one and the other ends of said slot respectively.

7. A hub as claimed in claim 6, wherein said housing has a radial flange prolonging said supporting surface.

8. A hub as claimed in claim 7, wherein said pawls have a hook defining a surface opposing said radial flange and parallel therewith.

9. A hub as claimed in claim 8, wherein each said pawl makes contact with said cam through a ball bearing mounted in said pawl.

'10. A hub as claimed in claim 9, wherein each said ball bearing is loosely mounted in a cavity of said pawl.

References Cited by the Examiner UNITED STATES PATENTS 1,530,991 3/1925 Forbes 24-2-7-2 2,211,472 8/1940 Klein et al. 242,7-2 2,983,460 5/1961 Wright 24.2-68.3 3,053,466 9/ 196 2; Rehklau 24 2-6 83 3,124,319 3/ 1964- Cohen et al 242-68.3

FRANK I. COHEN, Primary Examiner.

N. L. MINTZ, Assistant Examiner. 

1. A HUB FOR RELEASABLY HOLDING A REEL, SUCH AS A MAGNETIC TAPE REEL, COMPRISING A HOUSING HAVING AN EXTERNAL SUPPORTING SURFACE FOR SAID REEL AND BEING ADAPTED TO BE SECURED TO A ROTATABLE SHAFT, A PLURALITY OF PAWLS CARRIED BY SAID HOUSING AND CAPABLE OF BEING MOVED IN ONLY A RADIAL DIRECTION WITH RESPECT TO SAID HOUSING, SAID PAWLS EACH HAVING AN OUTER SURFACE FOR ENGAGING A SUPPORTING SURFACE OF SAID REEL, AND RESILIENTLY-BIASED, SNAP-ACTING; DISPLACEMENT MEANS INCLUDING A ROTATABLE KNOB AND ADAPTED TO ENGAGE SAID PAWLS WITH SAID REEL AND TO URGE SAID PAWLS OUT OF ENGAGEMENT WITH SAID REEL, SAID RESILIENTLY-BIASED, SNAP-ACTING DISPLACEMENT MEANS HAVING A FIRST STABLE POSITION AND A SECOND STABLE POSITION AND INCLUDING AT LEAST ONE CAM ABLE TO BE PIVOTED BY SAID KNOB ABOUT A PIVOT AXLE FROM SAID FIRST STABLE POSITION TO SAID SECOND STABLE POSITION AND MOUNTED IN SAID HOUSING IN SUCH A MANNER THAT WHEN SAID CAM IS PIVOTED INTO SECOND STABLE POSITION IT MOVES SAID PAWLS INTO ENGAGEMENT WITH SAID REELS. 